DE2635795A1 - PROCESS AND DEVICE FOR THE VERIFICATION OF DOCUMENTS - Google Patents

Description

LEfNWEBER & ZIMMERMANN

PATENT LAWYERS

ZDQO / 3 5 Dipl.-Ing. Hermann Leinweber Dipl.-Ing. Heinz Zimmermann Dipl.-Ing. A. Gf. v. Wengersky

8 Munich 2, Rosental 7

2. Entrance (Kustermann-Passage) Telephone (089) 2603989 Telex 528191 lepatd
Telegr. Addr. Leinpat Munich

^den - ¹ I. mfy. 1878

Our sign

DASY Inter S.A., Geneva / Switzerland

Method and device for checking the authenticity of

Documents

The invention relates to a method for checking authenticity of documents that have a function such as issuing money, passing a lock or the like. trigger. The invention further relates to an apparatus for carrying out this method.

There are several ways to legitimize a physical person for any function. In all However, a document is used as legitimation. This can be a bypass, an identity card or the like. Act. Check cards, credit cards or the like are often used to legitimize money transactions. used. A backup legitimation is also possible in the case of driving licenses or identity

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Cards desirable as they are given to their employees by companies or authorities. Such identity documents are usually provided with the name of the owner and other personal information. You can also take photographs and bear the signature of the holder.

If a single such document is sufficient to trigger the legitimation function, it can usually easily be forged. Even if additional, for example optically invisible or coded information is entered in the legit! mierungsdokument be included, a forgery [is easily possible, since in the event of loss of power are often possible in ί located Legitimierungsdokumentes change the photo 'or the signature of the holder or \ not even necessary to use around the Legitimierungsdokument [. For this reason, several documents with different functions to achieve the one desired function are often used to increase the protection against forgery useful, whereby these several documents only represent sufficient legitimation for the desired function in combination. For example, checks and credit cards are used together in money transactions. Passports and visas are also used jointly in cross-border traffic. Only both documents together result in the desired function of issuing money or allowing border crossings. This increases security, but it is still difficult and in some cases even impossible to determine whether the legitimation document is being used by its actual owner and within the limits set by the authentication of the legitimation document.

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For example, there is a need for the use of credit cards and monetary transactions based on credit cards safer than it was previously possible. Counterfeit credit cards or the use of a credit card a person other than the actual owner should be excluded. For example, it should also be made impossible exceed a credit limit set by the credit card. It is desirable that the tracking every transaction is made easier because of the credit card, regardless of whether transactions in Counter traffic or at machines.

In order to meet these requirements, a large number of systems have already been proposed ("Electronics" 29. March 1971 pages 42 to 48). The known systems facilitate cashless money transactions in various ways. In particular test terminals are used that carry out certain controls enable. These controls can consist, for example, of the magnetic stripe in the credit card (possibly in coded form) stored information about the maximum credit of the holder can be compared with the withdrawal amount. If the withdrawal amount exceeds the maximum credit granted to the holder, the payment will be rejected by the test terminal. If it does not exceed the maximum credit, the test terminal the payout is released, taking into account the coded information on the credit card at the same time the withdrawal amount is changed. Other test terminals are available through the public switched telephone network or otherwise connected to a central computer, which checks the credit card numbers and the account number, determines the account balance and releases the withdrawn amount used if the checks show a corresponding account balance.

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However, all of these systems have a relatively low level of security is against the use by persons who with the right-I moderate owner of the document are not identical.

Numerous other procedures have therefore already been proposed by which the security of Legitimie-I documents against forgery or unlawful use are to be increased. Cash dispenser machines are known

(DT-OS 21 19 491) in which to increase the security of ¹ machine readable bank card and the machine readable Sehecks: must be used by the check owner an additional code by hand before-ι-written location in the check, WO 'through the Check first received its value. This additionally from; The owner-registered code is checked in a test device I at the same time as the check card and check are checked. If the result of the test is positive, this is how-; then the special check issued, the withdrawal of money on; Allows cash dispensing machines. The disadvantage going in this Ver-I is the fact that in the checking the bank card, ■ the check and the additional code on the check controlled ^■: must be. It's time-consuming. In addition, an improvement in security is only achieved when using cash dispensing machines. With normal counter traffic in banks this still does not achieve absolute security,

! because checks are often paid out even if they have the additional, hand-entered code, the [Check card is not presented at the same time. That is a consequence of the fact that then the check is already in itself contains all the information that enables a withdrawal. ; Research in practice has shown that such does not ! are in compliance with the safety regulations

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Payouts in banks are often made to well-known bank customers despite the existing provisions. Ultimately but this also represents a reduction in security in check transactions. The same applies to credit cards or the like.

In addition, there is also a need for a method that verifies the authenticity of works of art, such as paintings to be able to check or, for example, the legitimation Unknown individuals to gain access to areas where confidential work is being carried out.

With all these identity safeguards the additional difficulty arises that not only one classification ' of the document must be achieved, but an individualization. In the case of banknotes of different values It is sufficient, for example, to make one hundred mark notes and one thousand mark notes distinguishable according to their material. on the same way could check cards with different withdrawal limits, driver's licenses different Class or motor vehicle certificates for LKV /, passenger cars, etc. can be distinguished from one another. But that's no longer enough if an assignment of a certain document to a certain owner or the differentiation of all individual Documents of a certain class is desirable. For example, the output of an identity document be possible for a Vdk of 100 million. In the Eegel is It is already out of the question here to even accommodate the distinguishing information on relatively small documents. In addition, identification errors often occur. Both apply in any case if the identification key is on should be introduced into the document in a hardly forgery-proof manner.

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The object of the invention is to propose a method and a device for checking the authenticity of documents, in the case of the individualization and identification of individual documents, the random arrangement of physical irregularities is used.

According to the invention, this object is achieved in that the document is provided with particles or locations which have physical properties that differ from the physical properties of the basic mass of the document, that these physical irregularities are particles or locations on or in the G- Round mass have a random distribution that the surface of the document is scanned in a predetermined and fixed scanning track by a detector responsive to the physical properties of the particles or locations, that the output pulses of the detector are assigned clock pulses, that the coincidence of output pulses of the detector with the The pulse pattern generated by clock pulses forms a binary code that the binary code . _{is compared with a previously produced in the same way, which also simulates and stores the random distribution of the physical irregularities, and that the function of the document is enabled if the two binary codes match.

It can first be seen that here the random arrangement of the scanned particles or the like serves as the identification code is evaluated. This fact leads to the fact that a certain document regarding its authenticity by the accidental Properties of its particle load is secured. Counterfeiting is practically impossible. It is there assume that the document will be issued with its random identification code with the help of a central

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tral computer is saved. Such a document is coming If it is lost or stolen before it is issued, the identification code associated with the document is stored in the central computer not saved. Even then, such a document will be deemed to have not yet been issued (blank) or falsified Document recognized that appears completely genuine with regard to all other information. Will the document after issuance stolen, i.e. the document and the associated random information for its identification are already stored in the central computer, a falsification is therefore not possible because a change in the printed information, the picture, the plastic cover or whatever detail, in any case also a change The result of the random information used for identification: One of the tiny particles falls off and is broken and thus multiplied or shifted slightly. The random information used for identification is already there changed and the document identifiable as forged. This is essentially independent of the type of the Random information serving and evaluated physical uniformity of the matrix is. In the case of the basic mass can it is the carrier mass of the document, the photo emulsion of the accompanying photograph or the printing ink act of the imprint. On the document there is an embedment in the mass or an embedment in surface layers conceivable. Finally, for example by spraying, an arbitrary distribution of points with other surface properties can be achieved can be achieved on the surface. The protection against forgery is not only achieved when the random information is stored in a central computer (on-line), but also achieved off-line if additional measures are taken are taken, as described in detail, for example, by the applicant / n of DT-OS 23 18 763.

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It should also be pointed out that the random information Of course, initially, since τοη was created during the production itself is not known to anyone. At the exhibition of the document, the random information is evaluated and noted for the first time in the predetermined scanning track. It is then determined whether another document with the same random information may already be in the I predetermined scanning track exists. If that which Hegel is not the case, the document is by its respective, now known random information identified and repeatedly identifiable.

From the above explanation it is clear that what is important for the identification is the exact position of the physical To determine irregularities in a coordinate system. The abscissa of this coordinate system is given by the Clock pulses formed. Since only when a clock pulse coincides with an output pulse from the detector If the output pulse is evaluated for the binary code to be produced, a high-precision scheme for recognition is obtained the random information. Since, moreover, one and the same scanning track is always evaluated from the same fixed starting point it is ensured that this scheme is precise in the case of repeated checks of the random information is the same over and over again. Laterally, the same scanning track is always the same due to the well-known self-centering of the scanning head or ensured by fixed stops. This ensures that the random information serving as the identification code always turns out to be the same in repeated controls.

For this it is of course necessary that also keep the timing by the clock identical

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will. This can be achieved, for example, by gives the time control to the document itself. That can be about in the form of a trace of marks applied to the document, which for example can be optical or magnetic. Ever The more different identification codes are, the finer the interrogation process is designed by the time control result for a given length of the scanning track. Accordingly, counterfeiting is also becoming increasingly difficult. In the case of a 5 cm long scanning track, it is possible, for example, to have 128 interrogation points lying next to one another along the scanning track to be provided. Even with half the number, every single person could basically be in a 500 million Equip people with an identity document that is based on the random information present in the predetermined scanning track clearly different from any other document.

The. Random information, which serves as an identification code, is typical like a fingerprint People. What both have in common is the fact that here coincidences are used as identification codes Artificially cannot be reproduced precisely because they came about by chance. A review is on but possible without further ado. It takes place in a coordinate system. The random arrangement of the scanned physical irregularities based on a fixed starting point in a register. This replica

always results the same. It can therefore actually serve to confirm identity. Moreover, it is now technolo- gy easy to implement. ι

In the document that triggers a function and that is for [

the random information required random physical

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Has irregularities, it can be a variety of different document types. The same protection is also possible, for example, for works of art, such as paintings, for which a verification of their identity is desired later. The system can even be used where a person is to be identified on the human body. Here, for example, instead of the surface of the document, the random information is sprayed onto the back of the person's hand. An exchange of the person between two controls when accessing a security area is then no longer possible. Usually, however, it is a document in which physical irregularities caused by the manufacturing process are used as random information. Instead, physical irregularities applied after manufacture can also be used. In all cases, it is crucial that the physical irregularities are random and not controllable, that they occupy a small area proportion of, for example, less than 5% in the scanning track and that at least 20 can be detected in the scanning track by the detector.

The physical irregularities present in the random distribution can, as already mentioned, be caused by the manufacture act randomly occurring particles or places. Examples of this are the magnetic holes in magnetic strips, how they are inserted into credit cards or the wood fibers in the paper. Also can be used in the manufacture Particles with different physical properties of the paper or plastic pulp are added from which the Document is produced. Finally, the physical irregularities in the random distribution can also occur according to the

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Manufacture to be applied to the surface of the document. Examples of this are spraying on a binder containing finely divided particles or a binder on the surface of the document in random distribution of corrosive material. Another possibility is to spray on a transparent one Lacquer containing magnetic particles. If you only use one varnish that has been sprayed on, the other one, for example Has reflective properties or a different color than the basic mass, this is also an optical evaluation of the random information possible by an optical detector, as is known, for example, from OCK technology. Particularly A detector that works with a laser is useful here. It is of course inevitable that through wear and tear the document edges may also lose the specified starting point of the scanning track. But it is for this known, if a scan does not produce the expected result, a slight shift in the scan track and repeat the scan. In today's test terminals, such repeated scanning is carried out with a made such a speed that thereby a delay in counter traffic or in triggering the desired Function practically does not occur.

In the following the drawings are based on united ^ times illustrated embodiments explained, which are shown in the figures. Show it:

Fig. 1 is a perspective view of an arrangement for checking the authenticity of a document without Clock track,

2 schematically shows a circuit of a device

for the authenticity check in the system according to FIG. 1,

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FIG. 3 shows a view corresponding to FIG. 1 with a! have a clock track in the form of visible marks . send document, '■

4 shows a view corresponding to FIG. 2 of the trains subordinate circuit,

5 shows a view corresponding to FIG. 1 of an embodiment with a magnetic clock track and a magnetic information track on the ^: document,

6 shows a view similar to FIG. 2 of the

management form according to Fig. 5 belonging circuit,

7a to 7f show the specific case in an embodiment according to FIGS. 3 and 4 the determination of an identification code,

Fig. 8 is a diagram for the detection of the

reliable reproducibility of the reproduction of the identification code,

FIG. 9 schematically shows an explanation for taking into account the results of FIG. evaluation, and

Fig. 10 is a view of a further embodiment.

The following description is carried out on the basis of a document, which has roughly the format of a credit card, but is an identification document, a driver's license or the like. The document 10 can be made of paper, plastic etc. exist. If necessary, it is also in a plastic sleeve locked in. Either the document itself consists of a particle-laden base mass or a Surface layer of the document, a photo, an imprint

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etc. In the example explained it is assumed that the Document 10 is produced from a matrix which, as indicated in FIG. 1, contains particles 11 (magnetic fibers). The particles 11 have a completely random position in the matrix of the document TO which is practically not controlled

; can be and arises during manufacture by itself.

; The random position and distribution of the particles 11 cannot therefore be reproduced and their distribution for each individual document 10 typical in a way that the fingerprint is individual and typical for each person.

Fig. 1 shows the document 10 with inserted particles 11, the sight of an arrow 12 under a stationary Magnetic head 13 is moved through, so that / a scanning track by a relative movement of the document 10 with respect to the magnetic head 13 is created. All that matters is this relative movement, which of course also comes from a movement of the magnetic head 13 can be achieved over the document 10. Complex shaped scanning tracks can be generated if both the document 10 and the magnetic head 13 are given motion at the same time. The magnetic head 13 is provided with lead wires 14 provided. In the path of movement of the document 10 is a light emitting diode 15 with connecting wires 16 and a lamp 17 is arranged opposite this on the other side of the movement path. When moving in the direction of the arrow ; 12, the document 10 is laterally guided precisely by stops 18 so that the magnetic head 13 is identical in each case ι scanning track of the document 10 scans. Instead of leading through

the stops 18 may also be a self-centering of the ^magnet: its head 13 is provided on the scanning trace by applying a stamp on] the document 10th In any case, gene therefor to sorting \ that the magnetic head in each case precisely the same sample;

track scans.

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FIG. 2 shows the circuit for evaluating that which is obtained when the scanning track is scanned and which is read out therefrom Identification codes. If the document 10 is moved in the direction of the arrow 12 τοη Fig. 1, its finally runs Rear edge from the area between lamp 17 and photodiode 15. The photodiode 15 is therefore from the lamp 1? irradiated and emits a stream that. is amplified in an amplifier 19 and given to a monoflop 20 (OS = one shot). This generates a gate pulse for an MD gate 21 and thus sets the evaluation in G-ang. Those scanned by the magnetic head 13 Particles 12 result in corresponding signals which are applied to a further input of the MD gate 21 via an amplifier 22 are. Finally, an oscillator 23 is connected to a third input of the MD gate 21, which has a sequence of Emits clock pulses with a fixed frequency.

The MD gate 21 only emits an output pulse when a simultaneous input is made on all three input lines Momentum is present. So it is the length of the effective scanning track by the pulse duration of the output from the monoflop 20 Impulse determined. An output signal of the MD-To.rs 21 occurs within this pulse duration if one the output pulses of the amplifier 22 with a clock pulse from the output of the oscillator 23 coincides. Such an ■ The output signal of the MD gate 21 is fed into a shift register 24, which in turn receives the clock pulses from the oscillator 23 received as shift pulses (shift). The shift register 24 has as many storage locations as there are from the oscillator 23 clock or shift pulses are emitted within the sampling time determined by the monoflop 20. After completion the scanning (return of the monoflop 20 to its starting position) is thus in binary recording in the shift register a key of the random information

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by the distribution of the particles 11 in the document 10 along represents the identification code derived from the scanning track.

Of course, FIG. 2 is shown in a very simplified manner. In particular, there are the various common pulse shaping elements not listed, which are self-evident for a person skilled in the art. For example, the pulse obtained from the magnetic head 13 of an integration of its Subject to rising edge in order to achieve clear pulse peaks. It is also useful in the signal path to switch on an amplitude blocking element which only allows signals with an amplitude exceeding a threshold value to pass through. In this way errors are eliminated.

In Fig. 2, a counter 25 is indicated by dashed lines. Namely, it is possible to use those obtained from the magnetic head 13 To subject output signals to a counting process. Since the scanning track is known, this counting process enables to determine the number of particles 11 per unit area of the document 10 and thus to classify the document. This provides additional security because only those documents are recognized as genuine, which meet certain classification requirements suffice. For example, a different particle density can be used for driving licenses than for identity documents. A distinction can also be made between driving licenses of different classes will. In addition to the classification, the counter 25 also has a further function. The delicacy of the time locking "by the Clock pulses from the oscillator 23 can of course advantageously be adapted to the particle density in the document 10. This happens for example in that the counter 25 controls the oscillator in accordance with the result of the classification carried out

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: adjusts to an oscillation frequency corresponding to the particle density.

In practice, it is also possible to advance the document to be carried out with a stepper motor or a synchronous motor, which is controlled by the fundamental frequency of the oscillator 23.

The evaluation circuit shown in Fig. 2 can be isolated find use in an off-line terminal. The identification code must then be in encrypted form (see DT-OS 23 18 763) are available on the document. For example the binary memory content of the shift register is read out as a decimal number and printed. This number can be easy be encrypted by using a memory location key such as the first memory location is rated as 2 °, the second as 2, the third as 2, and so on. The possibilities are endless. Also is about that Determination of decimal numbers facilitates control by the off-line staff. However, it is particularly effective when when the output signal of the UHD gate 21 is fed to a modem which is in connection with a central computer in which the identification code resulting from the random information of the document is saved. The oscillator 23 can be replaced by a timing device similar to the Shift register only supplies signals that generate signals in one location time, e.g. four milliseconds. In the embodiment of FIG. 2, the clock is included in the device. It however, it is also possible and often expedient to use the clock generator ■ to be attached to the document 10 itself.

; Fig. 3 shows an embodiment in which the document: ! 10 carries a clock track 26 which consists of j affixed brands. In the example shown, j

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the brands made of fluorescent material. The marks 26 are illuminated by a lamp 27 and scanned by a photodiode 28.

Fig. 4 shows the associated evaluation circuit. The photodiode 28 is followed by an amplifier 29, at whose output the pulse sequence caused by the mark of the clock track 26 fixed frequency is available. This pulse sequence is applied on the one hand to a monoflop 30, which again the The length of the scan is determined, on the other hand to an AND gate 31, at whose second input the output signal of the monoflop 30 lies. At the output of the AND gate 31 is that of the Photodiode 28 by scanning the marks of the clock track 26 generate pulse sequence as long as an output signal of the monoflop 30 is present. The output signals of the AND gate 31 are used again a double purpose: once as a shift pulse for the shift register 24, on the other hand as clock pulses for controlling the scanning. As such, they will be sent to an entrance of one AND gate 32 placed, at the other input of which again the scanning of the particles 11 in the document 10 through the magnetic head 13 resulting pulses are applied through an amplifier 22. The AND gate 32 indicates a pulse the shift register 24 when an output signal of the amplifier 22 at its one input with a clock pulse at its other Entrance coincides. In this way, the random arrangement of the particles 11 in the document 10 is also here again simulated along the scanning track by the binary pulse storage in the shift register 24.

FIGS. 5 and 6 serve to explain a further embodiment. The document 10 with particles 11 here has j additionally a magnetic information track 33 and a magnetic clock:

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track 34 on. On the magnetic information track 33, any Information to be recorded with the document. The magnetic clock track 34 is with a frequency described, which acts upon scanning in the same way as the marks of the clock track 26 in the embodiment according to FIG. 3. A is used in this embodiment Triple magnetic head 35, which is also the magnetic information track 33, the Magnetaktspur'34 and the scanning track of the document 10 scans to determine its identification code. The details are indicated in Fig. 6: The triple magnetic head 35 three amplifiers 36, 37 and 38 are arranged downstream. The information is further evaluated in any way. the Information from the clock track and from the scan track is given to the MD port 32 in the manner described above and in the shift register 24 is stored, which also receives the required shift pulses from the clock track. In Fig. 6, a control for the start and end of the effective scan is not shown. There are also details here again with respect to pulse shaping and the like. The shift register 24 in Fig. 6 indicates which type is the memory content of the shift register. An occurrence will be explained next.

FIGS. 7 a to 7f serve to explain how the memory content in the shift register 24 comes about.

Fig. 7a shows the document 10 with particles 11 and the [

Clock track 26 from individual marks 39, which correspond to the long edge of the |

Document 10 along side by side at fixed intervals ^;

are arranged. The clock track 26 lies parallel to a scanning track 40 indicated by hatching in FIG. 7a. Since the for scanning serving magnetic head not only a gap width in the scanning direction, but also a certain gap length transversely to the scanning

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direction, the scanning track 40 also has a certain width. The arrangement of the particles 11 is purely random. However, it is through stops or self-centering of the magnetic head It is ensured via the scanning track 40 that the magnetic head scans the same scanning track 40 identically in each case.

Figures 7b to? D are in spatial assignment to Document 10 shown. In reality, however, the pulse trains shown are a representation in which the pulse amplitude is used as the ordinate and time is used as the abscissa. Such a representation arises when the document 10 of Fig. 7a is moved to the left past a stationary magnetic head. To make it easier to understand, however, is the spatial assignment of the individual pulses in FIGS. 7b to 7d to the conditions on the document 10 or to the places of the shift register 24 by superposing the figures underlined, whereby the assignment is visually highlighted by two vertical dashed lines.

Fig. 7b shows the amplified to saturation output signal of the amplifier 29 of FIG. 4. It is a Pulse train of a fixed frequency, that is to say the clock pulses that are generated by scanning the marks 39 of the tracer track 26 with the aid of the Photodiode 28 and the lamp 27 result.

7c shows the output signal of the magnetic head 13 of Fig. 4 in the form of an unbalanced analog signal. There is always a pulse peak when in the scanning track 40 a particle 11 lies under the magnetic head 13. The momentum amplitudes are still dependent on whether the particles lie on the surface of the matrix or are embedded deeper in the matrix. In the 4o scanning track of the i

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Document 10 is a particle 11 on the far right in FIG. 7a indicated by dashed lines. This is meant to express | that this particle is deeply embedded in the basic mass is, so that it results in a signal of reduced amplitude during scanning, as can be clearly seen in FIG. 7c is. The scanning track 40 also only covers very little Fibers result in pulses of reduced amplitude, as is the case, for example, in FIG. 7c with the third pulse of is indicated on the left. In order to create unambiguous relationships, the procedure is that by means of an amplitude lock a threshold value 41 is set in the downstream amplifier 22 and only those pulses are fed to the evaluation whose amplitude is above this threshold value 41 lie.

FIG. 7d shows the output signal, amplified to saturation, of the amplifier 22 of FIG. 4, which is a multi-stage Is amplifier, with amplitude lock and saturation amplification being carried out in the various stages.

Fig. 7e now shows the output of the AND gate 32, that is those pulses which are offered to the shift register 24. It can be seen that such an output pulse from the AND gate 32 is only present when clock pulses according to FIG. 7b with signal-j. pulses according to Fig. 7c coincide.

Fig. 7f shows how the simulation of the random vibration looks through the particles in the scan track 40 in the shift register 24. One representation is thereby corrected, that of those of Fig. 7d corresponds. This representation can be transferred can easily be implemented in practice by the corresponding direction of storage in the shift register 24,

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It can therefore be seen that the random arrangement of the particles Π in the scanning track of the document 10 is actually precisely controlled can be. As a result, since random information is assumed, a largely forgery-proof system.

FIG. 8 serves to demonstrate the fact that one actually obtains well reproducible results. The figure was produced with a document 10 which contained forty-two particles in a scanning track 40 which, when scanned, gave a pulse of sufficient amplitude. Five scans were taken in succession. Thereby, 27 pulses according to FIG. 7d occurred in all five scans. Five pulses are only recorded with four scans, three pulses with only three scans, two pulses with only two scans and finally five pulses appeared only with a single scan. It is now easily possible to use only those 27 pulses for the identification code that are recorded in all runs. For this it is sufficient to carry out several runs each time the document is issued by an exhibition terminal and only evaluate those impulses for the identification code that are sure to occur in all runs using the evaluation circuit. The uncertain are not evaluated, which is possible by assigning them to the associated clock pulse. By appropriate formwork \ tung technical measures, it has been found possible to bring the value of all runs covered impetus to over 80 ° i j and corresponding effort to nearly 100 ^a ß>. j In addition, the execution of several runs at the

Evaluation considering the speed of the test none * - lei difficulty. Terminal constructions are particularly suitable for this, in which the document is firmly inserted and

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in which the detector moves several times along the scanning track, and is moved.

Fig. 9 shows how the results τοη Fig. 8 in the Evaluation are taken into account. The shift register 24 is shown twice one above the other, the counts at two different evaluations were carried out. It can be seen that the information shifted into the shift register match with the exception of fourth place. here it is therefore an uncertain evaluation. This place concerns one of the impulses that do not appear on every run. This fact is taken into account simply by the fact that a code key affixed to the Dokumai 10, for example indicates where the starting point of the code track to be scanned lies, information is also given about it, that the fourth memory location is not taken into account in the evaluation. In this way, the unsafe impulses can be completely switched off during the evaluation. Clear evaluation conditions are then ensured in each case.

Fig. 10 shows an embodiment in which the system is further refined. The document 10 carries the previously explained clock track 26, but it is perpendicular to this additionally a similarly structured local track 42 is provided. You can use this location track 42 to the scanning head J center on the correct track. However, for example, the identity of the document 10 can also be secured by: are constantly changed that one year, for example, ι the second mark of the location track 42 is used to define the scanning track, next year the fifth mark and so on. The security of the document's identity changes and is even more difficult to falsify because not only the

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Information content of a single scanning track, but the information content numerous scanning tracks on the entire document 10 would have to be reproduced in the event of a forgery. What Already seems practically impossible with a single scanning track, is not at all with numerous scanning tracks to realize more. A document forgery for a short time However, the period is largely uninteresting. In addition, it is with the help of the local track 42 and the marks provided there possible, with a single scanning movement of a magnetic head 13, several mutually paisLlele scanning tracks simultaneously to be filled and saved. This way the number becomes the information obtained during a relative movement between magnetic head 13 and document 10 for a certain distance multiplied, making the system even safer.

Clock track 26 and location track 42 complement each other to form a complete coordinate system.

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Claims (12)

. Patent claims: Procedure for checking the authenticity of documents that a function such as issuing τοη money, passing a lock or the like. trigger, characterized in that the document is provided with particles or sites that have physical properties that differ from the physical Properties of the basic mass of the document differ in that these physical irregularities represent particles or place a random distribution on or in the basic mass have that the surface of the document in a predetermined and fixed scanning track from one to the physical Properties of the particle or body responsive detector is scanned that the output pulse of the detector clock pulses assigned that the generated by coincidence of output pulses of the detector with the clock pulses Pulse pattern forms a binary code that the binary code with a previously prepared in the same way, also the Random distribution of the physical irregularities simulating and stored binary code is compared, and that the function of the document is released when the two binary codes match. 2. Apparatus for carrying out the method according to claim 1, characterized in that one of the physical irregularities present in random distribution in the document (10) responsive detector (13, 35) is provided that a drive device the predetermined scanning track (40) generated by a relative movement of the detector and document that the output pulse of the detector (13, 35) and a clock (23, 26) can be stored in a register (24) via an AND gate (21, 32), and that the% ister (24) the - 25 7098 11/0942 Random distribution of the physical irregularities in the Scanning track (40) simulates. 3. Apparatus according to claim 2, characterized in that the physical irregularities are magnetic particles (11) are. 4. Apparatus according to claim 2 or 3, characterized in that the scanning track (40) on the document (10) Coordinate system is superimposed, which defines scanning points along the predetermined scanning track. 5. Apparatus according to claim 4, characterized in that that the abscissa of the coordinate system is formed by a clock track (26) forming the clock generator. 6. Apparatus according to claim 5, characterized in that that the clock track (26) consists of marks (39) whose physical properties differ from the basic dimensions of the document (10) differentiate. 7. Apparatus according to claim 6, characterized in that the marks (39) are optical or magnetic marks. 8. Device according to one of claims 3 or 5, characterized in that the particles or marks are invisible! are cash. j 9. Device according to one of claims 5 to 8, j characterized in that the ordinate of the coordinate system consists of a location track (42), which in turn consists of a row is formed by marks that are perpendicular to the clock track (26). - 26 - 709811/0942 10. The device according to claim 9, characterized in that in each case at the intersections of by the marks Clock track (26) or the local track (42) certain straight lines Presence or absence of a physical irregularity (particles 11) in the document (10) can be determined. 11. The device according to claim 2, characterized in that the register (24) is a shift register. 12. Device according to one of claims 1 to 11, characterized in that the document (10) moreover an encrypted Has information on the random distribution of the physical irregularities or the corresponding binary code. 709811/0942 lee